Ferroelectric properties of Ce³⁺- doped Aurivillius K_0.5Bi_4.5Ti₄O₁₅ thin films

The effect of Ce³⁺-ion doping on the structural, electrical and ferroelectric properties of the Aurivillius K_0.5Bi_4.5Ti₄O₁₅ thin films are reported. For the purpose of this study, K_0.5Bi_4.5Ti₄O₁₅ and K_0.5Bi_4.0Ce_0.5Ti₄O₁₅ thin films were deposited on Pt(111)/Ti/SiO₂/Si(100) substrates by using chemical solution deposition method. Formation of the Aurivillius structure was confirmed through X-ray diffraction and Raman scattering studies. From the experimental results, tremendous improvements in the electrical and the ferroelectric properties were observed for the K_0.5Bi_4.0Ce_0.5Ti₄O₁₅ thin film. The ferroelectric polarization-electric field (P-E) hysteresis loops study showed a largely enhanced remnant polarization (2P_r), with a value of 52.8 μC/cm² for the K_0.5Bi_4.0Ce_0.5Ti₄O₁₅ thin film measured at an applied electric field of 595 kV/cm. Furthermore, a low leakage current density value of 1.38×10⁻⁸ A/cm² was measured at an applied electric field of 100 kV/cm for the K_0.5Bi_4.0Ce_0.5Ti₄O₁₅ thin film.